This invention relates to a keeper lock for a zipper-type slide fastener having a lacing element, and in particular, to a lock of the type disclosed in U.S. Pat. Nos. 3,070,986, 3,580,016 and 3,785,185.
The keeper locks with which the present invention is concerned are constructed for use in connection with the slide fastener of a flexible fabric money bag or other enclosing means or container. The locks serve to retain or trap the lacing element of a slide fastener with the fastener closed, to prevent operation of the fastener and thus prevent unauthorized access to the contents of the bag or other enclosing means.
The keeper locks of the above-identified patents each embody a tubular lock barrel which is fastened to the pouch of a money bag. In U.S. Pat. No. 3,070,986, a lock cylinder rotates in the barrel, and a keeper arm fixed to the cylinder rotates therewith, between slide fastener locking and unlocking positions. One disadvantage of such a structure is that it is relatively susceptible to picking. Another disadvantage of the structure is that it is vulnerable to damage to its tumbler elements when torque is applied to the keeper arm, to the extent of breakage, so that the lock is forced open.
U.S. Pat. Nos. 3,580,016 and 3,785,185 disclose keeper locks which embody improvements on the foregoing structure. The improvements include the provision of an intermediate tubular handle, disposed between the lock barrel and the lock cylinder. In such structure, the keeper arm is affixed to the handle. The locks of the latter patents have a so-called "pop-up" structure, wherein the handle and cylinder are elevated or "pop up" upon unlocking, and are rotated to an out-of-the-way keeper arm position when elevated. The structure of U.S. Pat. No. 3,070,986 involves no elevation of parts, but the lock cylinder remains in a constant axial disposition relative to the barrel.